Many tractor drivetrains run transmission, final drives and hydraulics on a single oil, so the fluid must do two opposite jobs: protect gears under load and control friction in wet brakes and clutches. That is why UTTO oils include carefully tuned friction modifiers and anti-foam agents; too little and you get brake chatter, too much and clutches slip. They also use demulsifiers so small water ingress separates and can be drained instead of circulating as an emulsion—a quiet safeguard in Nordic humidity and slush. The same principle applies to UTTO TO-4 SAE30, where shift feel, brake silence and pump feed all depend on the additive balance, not just the viscosity grade.